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    Subject[PATCH v12 4/4] gpio: xilinx: Utilize generic bitmap_get_value and _set_value
    This patch reimplements the xgpio_set_multiple() function in
    drivers/gpio/gpio-xilinx.c to use the new generic functions:
    bitmap_get_value() and bitmap_set_value(). The code is now simpler
    to read and understand. Moreover, instead of looping for each bit
    in xgpio_set_multiple() function, now we can check each channel at
    a time and save cycles.

    Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
    Cc: Michal Simek <michal.simek@xilinx.com>
    Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
    Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
    ---
    Changes in v12:
    - Remove extra empty newline.

    Changes in v11:
    - Change variable name 'flag' to 'flags'.

    Changes in v10:
    - No change.

    Changes in v9:
    - Remove looping of 'for_each_set_clump' and instead process two
    halves of a 64-bit bitmap separately or individually. Use normal spin_lock
    call for second inner lock. And take the spin_lock_init call outside the 'if'
    condition in the 'probe' function of driver.

    Changes in v8:
    - No change.

    Changes in v7:
    - No change.

    Changes in v6:
    - No change.

    Changes in v5:
    - Minor change: Inline values '32' and '64' in code for better
    code readability.

    Changes in v4:
    - Minor change: Inline values '32' and '64' in code for better
    code readability.

    Changes in v3:
    - No change.

    Changes in v2:
    - No change

    drivers/gpio/gpio-xilinx.c | 65 +++++++++++++++++++-------------------
    1 file changed, 32 insertions(+), 33 deletions(-)

    diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
    index 67f9f82e0db0..3ba1a993c85e 100644
    --- a/drivers/gpio/gpio-xilinx.c
    +++ b/drivers/gpio/gpio-xilinx.c
    @@ -138,37 +138,37 @@ static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
    {
    unsigned long flags;
    struct xgpio_instance *chip = gpiochip_get_data(gc);
    - int index = xgpio_index(chip, 0);
    - int offset, i;
    -
    - spin_lock_irqsave(&chip->gpio_lock[index], flags);
    -
    - /* Write to GPIO signals */
    - for (i = 0; i < gc->ngpio; i++) {
    - if (*mask == 0)
    - break;
    - /* Once finished with an index write it out to the register */
    - if (index != xgpio_index(chip, i)) {
    - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
    - index * XGPIO_CHANNEL_OFFSET,
    - chip->gpio_state[index]);
    - spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
    - index = xgpio_index(chip, i);
    - spin_lock_irqsave(&chip->gpio_lock[index], flags);
    - }
    - if (__test_and_clear_bit(i, mask)) {
    - offset = xgpio_offset(chip, i);
    - if (test_bit(i, bits))
    - chip->gpio_state[index] |= BIT(offset);
    - else
    - chip->gpio_state[index] &= ~BIT(offset);
    - }
    - }
    -
    - xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
    - index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
    -
    - spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
    + u32 *const state = chip->gpio_state;
    + unsigned int *const width = chip->gpio_width;
    +
    + DECLARE_BITMAP(old, 64);
    + DECLARE_BITMAP(new, 64);
    + DECLARE_BITMAP(changed, 64);
    +
    + spin_lock_irqsave(&chip->gpio_lock[0], flags);
    + spin_lock(&chip->gpio_lock[1]);
    +
    + bitmap_set_value(old, state[0], 0, width[0]);
    + bitmap_set_value(old, state[1], width[0], width[1]);
    + bitmap_replace(new, old, bits, mask, gc->ngpio);
    +
    + bitmap_set_value(old, state[0], 0, 32);
    + bitmap_set_value(old, state[1], 32, 32);
    + state[0] = bitmap_get_value(new, 0, width[0]);
    + state[1] = bitmap_get_value(new, width[0], width[1]);
    + bitmap_set_value(new, state[0], 0, 32);
    + bitmap_set_value(new, state[1], 32, 32);
    + bitmap_xor(changed, old, new, 64);
    +
    + if (((u32 *)changed)[0])
    + xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET,
    + state[0]);
    + if (((u32 *)changed)[1])
    + xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
    + XGPIO_CHANNEL_OFFSET, state[1]);
    +
    + spin_unlock(&chip->gpio_lock[1]);
    + spin_unlock_irqrestore(&chip->gpio_lock[0], flags);
    }

    /**
    @@ -292,6 +292,7 @@ static int xgpio_probe(struct platform_device *pdev)
    chip->gpio_width[0] = 32;

    spin_lock_init(&chip->gpio_lock[0]);
    + spin_lock_init(&chip->gpio_lock[1]);

    if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
    is_dual = 0;
    @@ -313,8 +314,6 @@ static int xgpio_probe(struct platform_device *pdev)
    if (of_property_read_u32(np, "xlnx,gpio2-width",
    &chip->gpio_width[1]))
    chip->gpio_width[1] = 32;
    -
    - spin_lock_init(&chip->gpio_lock[1]);
    }

    chip->gc.base = -1;
    --
    2.26.2
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